[Coco] Re: Bellingham User Group Stuff

[Gene Heskett]

On Wednesday 04 February 2004 09:46, Boisy Pitre wrote:
>On Feb 3, 2004, at 9:26 PM, Gene Heskett wrote:
>> On Tuesday 03 February 2004 17:57, Boisy Pitre wrote:
>>> I suspect that bit 1 of byte $10 in LSN0 is not set. It should
>>> be, indicating to the driver that the disk is formatted as a
>>> 96tpi disk.
>>>
>>> Look at offset $10 of LSN0 of the disk image.  It should be $03,
>>> not $02.
>>>
>>> Boisy
>>
>> That would depend on whether he wrote them to a 5.25", or to a
>> 3.5" diskette.  The 3.5 was 135 tpi from the gitgo, so that bit
>> should not be set for a 3.5" formatted disk as there is never a
>> chance of a tpi miss-match there.
>
>Gene,
>
>Thanks for the clarification.  You're correct: 135 tpi is the actual
>setting for 3.5" drives.
>
>In my experience with the current cc3disk driver, you MUST set bit 1
> of offset $10 in LSN0 of a disk image, in order to properly
> read/write that image on a 3.5" 720K floppy disk.
>
>Boisy

Bit 1, or bit 0?  But 0 should be set in any event as thats the 
double-density bit.

I don't believe I have that bit 1 set here, and its working ok.

Your descriptor that you use with a 3.5 disk should have DNS=1 when 
the  disk is formatted.  Or at least thats what I'm using here.  And 
because the question hadn't come up before, I've not run ded against 
a 3.5 disk to see what offset $10 actually is.  I may do that this 
afternoon to verify & get back to you.

I also hope you get this, the last message I got from the princeton 
server was that my message was being held for approval.  So I've Cc: 
thru malted media too.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.22% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attornies please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.